1. Field of the Invention
The present invention relates to a phosphor used in a display device such as an LED, CRT, PDP, FED, and EL, and a lighting unit such as a vacuum fluorescent display (VFD) and fluorescent lamp, the phosphor being particularly suitable for an LED, a light source, and a lighting unit each of which has a light emitting portion of ultraviolet-blue light or the like and emits visible or white light.
2. Description of the Related Art
An LED, a light source and a lighting unit are known, which emit white light by a combination of a light emitting element which emits blue or ultraviolet light and a phosphor which has an excitation band in the ultraviolet-blue wavelength region generated from the light emitting element.
As the phosphor used in the LED and the like, Y2O2S:Eu, La2O2S:Eu, 3.5MgO.0.5MgF2.GeO2:Mn, and (La, Mn, Sm)2O2S.Ga2O3 are known as a red phosphor, ZnS:Cu,Al, SrAl2O4:Eu, and BAM:Eu,Mn are known as a green phosphor, YAG:Ce is known as a yellow phosphor, and BAM:Eu, Si5 (PO4)3Cl:Eu, ZnS:Ag, and (Sr, Ga, Ba, Mg)10(PO4)6Cl:Eu are known as a blue phosphor. Then, an LED, a light source and a lighting unit of white or monochromatic light can be obtained by combining these phosphors and a light emitting element.
As a phosphor for a white LED, there are suggested an oxynitride glass phosphor (refer to Patent Document 1) a phosphor having a sialon as a host material (refer to Patent Documents 2 and 3), and a phosphor including, nitrogen of a silicon nitride group or the like (refer to Patent Documents 4 and 5), and there is further suggested a lighting device using these phosphors.
[Patent Document 1] Japanese Patent Application Laid-open No. 2001-214162
[Patent Document 2] Japanese Patent Application Laid-open No. 2003-336059
[Patent Document 3] Japanese Patent Application Laid-open No. 2003-124527
[Patent Document 4] Translated National Publication of Patent Application No. 2003-515655
[Patent Document 5] Japanese Patent Application Laid-open No. 2003-277746